The Bogalusa Heart Study is a long-term epidemiologic program studying the Early Natural History of Arteriosclerosis (atherosclerosis and essential hypertension). A total and well defined, bi-racial, (black-white) pediatric population is being studied. Epidemiologic investigations on cardiovascular (C-V) risk factor variables using a mixed cross-sectional and longitudinal design now constitutes an extensive data base on some 10-12,000 individuals, from birth to 31 years. Cardiovascular risk factor/variables and lifestyles, i.e., diet, tobacco and alcohol use, have been studied intensively. Secular trends over time are observed as part of the natural history and as a basis for evaluating changes that occur in longitudinal cohorts. Longitudinal observations now span fifteen years to note the predictive nature of risk factors and the potential for identifying young individuals at risk for early heart disease. Observations focus on the distributions and prevalence, inter-relationships, and time-course changes of risk factors important in the pathogenesis of atherosclerosis, essential hypertension, and obesity. We propose to continue these studies with emphasis now being placed on a follow-up of young adults who have been examined earlier, as they mature and as some develop abnormal levels of C-V risk factors and even clinical disease. We will study carefully selected individuals and their families to explore, in a Follow-up Clinic, determinants and clinical evidence of hypertension and hyperlipidemia. In an effort to study the "evolution of disease" in these young adults a unique set of information is available from prior examinations. In depth studies will be conducted with the potential of understanding both genetic and environmental interactions underlying C-V disease. An important on-going study complementing the natural history risk factor observations involves a necropsy study of children and young adults having accidental deaths. Autopsy studies provide a unique opportunity to observe anatomic C-V and renal changes to antemortism C-V risk factors. It is becoming apparent that serum total cholesterol and LDL-C relate to fatty streaks in the aorta, while multiple risk factors, especially high VLDL-C, low HDL-C, blood pressure, obesity, and smoking relate to fatty streaks in the coronary vessels. Further studies, including histologic observations, are planned to obtain greater insight into these associations, especially race, sex divergence. The overall umbrella of the Bogalusa Heart Study now provides a resource for hypothesis testing and Special Studies related to lipids, blood pressure and obesity. A number of proposed collaborative studies, nationally and internationally, involve the potential of generating significant lipoprotein and apoprotein data regarding families with low HDL-C and apo A-1, apo E isoforms, LP(a), as well as information on relevant candidate gene markers for CHD in three generational family clusters. Studies of the genetic and environmental interaction of this bi-racial population are providing clues to mechanisms of the early development of coronary atherosclerosis and essential hypertension. Observations from the Bogalusa Heart Study will also provide a rational background for prevention programs starting in early life.